Generally, a frame of a blower (i.e. a fan frame) can be separated into two pieces. In other words, a fan frame is detachably assembled by an upper housing and a lower housing. The upper housing and the lower housing are jointed by screw-locking junction, plastic-melting junction, mechanism-snapping junction, cylinder-riveting junction or flange-riveting junction. Although the junction can be implemented by the above-mentioned methods, an accuracy error while matching, an alignment error while assembling, residual stresses while forcing are possibly occurred, thereby forming gap or deforming the product of the fan. In particular, the fan may be broken.